"There's kind of a joke in the military that if you go out and kill 100 people as a civilian, you're thrown in jail, but if you do it as a soldier, you get a bunch of medals," he says with a chuckle.

The man, whom I'll call "Ben" because he prefers to remain anonymous, tells me he was in the Air Force for four years, from 2002 to 2006. He claims to have been diagnosed with antisocial personality disorder (ASPD) in 2005.